Okay, this one’s going to take a bit of unpacking.
First off: October 3 is the birthday of Madoka Kaname, the main character of 2011 anime series Puella Magi Madoka Magica.
Second: there’s a pachinko parlor in Akihabara called Island that’s known for its quantity of Puella Magi Madoka Magica pachinko machines.
Put them together, and what do you get? 4,200 humans lining up on the streets of Akihabara to pay tribute to Madoka via a few rounds of pachinko.
That’s the word from Island itself, which reported the number at 8:42 (it opens at 10AM). Island also tweeted thanks to its consumers and politely reminded them that it’s illegal to smoke on the street in Chiyoda-ku, where Akiba is located.
— アイランド秋葉原店 (@akiba_island) October 3, 2019
It was speculated that because of the birthday celebrations, some of the machines were set to pay out more pachinko balls than usual, so the line was probably a mix of Madoka fans and those looking for some easy winnings.
Puella Magi Madoka Magica is, of course, the hit 2011 magical girl series that Aniplex describes like this:
“Has a loving family and best friends, laughs and cries from time to time…” Madoka Kaname, an eighth grader at Mitakihara middle school, lives such a life. One day, she has a very magical encounter. She doesn’t know if it’s by chance or by fate yet, but this meeting will change her destiny. This is the beginning of a new story of magical girls…
— ﾂﾙﾐﾛﾎﾞ (@kaztsu) October 2, 2019